
#ifdef GL_ES
precision mediump float;
#endif

const float PI=3.1415926535;

uniform vec2 u_resolution;
uniform float u_time;

void main(){
    vec2 coord=(gl_FragCoord.xy * 2.0 - u_resolution)/min(u_resolution.x,u_resolution.y);
    coord.x +=sin(u_time)+cos(u_time*2.1);
    coord.y +=cos(u_time)+sin(u_time*1.3);
    float color = 0.0;
    
    color += 0.1*abs( sin(u_time)+0.03)/length(coord);
    
    gl_FragColor=vec4(vec3(color),1.0);
}